Ecological momentary assessment (EMA) is a real-time sampling strategy that may address limitations in health research, such as the inability to examine how processes unfold on a daily basis. However, EMA studies are prone to limited data availability due to difficulties in implementing sophisticated protocols and systematic non-compliance with prompts, resulting in biased estimates and limited statistical power. The objectives of this study were to describe the availability of data, to examine response patterns, and to analyze factors related to EMA prompt compliance in a dyadic EMA study with mothers and children. Participants (N = 404) each received up to eight EMA prompts (i.e., audible pings) per day for a total of 7 days. Each EMA survey consisted of items assessing affect, perceived stress, and social context. Participants responded to approximately 80% (range: 3.4%-100%) of prompted EMA surveys, and completed 92.6% of surveys once started. Mothers and children identifying as Hispanic, as well as mothers in lower-income households, were less likely to comply with any given EMA prompt. Participant dyads were more likely to comply with prompts when they were together. Understanding factors related to systematic EMA prompt non-compliance is an important step to reduce the likelihood of biased estimates and improve statistical power. Socioeconomic factors may impede mothers' compliance with EMA protocols. Furthermore, mothers' presence and involvement may enhance children's compliance with EMA protocols.